The invention relates to a method and a device for operating a switching element. The invention further relates to an electrical system comprising the device, to a computer program for carrying out said method and also to a machine-readable storage medium.
Switching elements, in particular power semiconductor switches, possess a temperature-dependent dielectric strength. In this context, dielectric strength means the ability of a switching element to isolate a voltage applied to the two poles of the switching element in the open state permanently and reliably from one another. At relatively low temperatures, the dielectric strength of a switching element is 600 V, for example. This means that the switching element is designed in such a way that it permanently isolates a voltage of 600 V applied to the poles thereof. At relatively high temperatures, the same switching element is able to isolate voltages of approximately 750 volts from one another. An increase in the dielectric strength of switching elements can be observed within certain limits. For the operation of robust electronic circuits, there is provision for only that voltage that can be reliably isolated by the switching element at the lowest operating temperatures of the circuit to be permitted as the maximum voltage at the poles of the switching element. The potential of the switching elements is therefore not utilized at relatively high operating temperatures, at which even a relatively high voltage at the poles of the switching element would be able to be reliably isolated, and therefore a relatively high power would be able to be switched.
It is accordingly known practice from the prior art, for example from DE 10 2006 047 243 A1, to operate a motor vehicle on-board electrical system using a power transistor, wherein the electrical circuit is configured in such a way that voltages that would exceed the dielectric strength of the transistor are not able to occur.
There is the need to develop alternatives to this that make it possible to utilize the relatively high dielectric strength of switching elements at relatively high temperatures.